BBC Radio 4's flagship investigative programme, File On 4, has been made at the BBC in Manchester since 1977.

Since its first investigation, an examination of governmental wage policy, the programme has won over 40 awards, including three prestigious Sony Golds.

Established by former BBC Radio 4 controller, Michael Green, File On 4 has investigated a wide range of topics and home and abroad. Food aid fraud, football hooliganism, joyriding and police marksmen are just some of the issues the programme has explored in depth.

File On 4 has heard from some of the BBC's most accomplished journalists, with Bridget Kendall, Stephen Sackur, Robin Lustig, Justin Webb, Winifred Robinson and Nick Clarke all having reported for the programme.

FILE ON 4 AT 25

Helen Boaden's 1986 report on AIDS in Uganda was one of three Sony Gold winners

Many of File On 4's most significant investigations are described in a special web tribute produced to mark its 25th anniversary in 2002.

In 2003, the programme won the highly coveted Sony Gold Award for its investigation into cot deaths which brought to light crucial new evidence that helped to quash Sally Clark's conviction.

Praising the programme as a "journalistic tour de force", Sony's judges said: "Now that Sally Clark's conviction has been quashed, everyone is on the bandwagon - but this programme was made whilst she was in prison.

"It was brave, compassionate and unswerving in its sense of the injustice done."

Another triumph came at the international George Peabody Awards for excellence in media. One of the winners of the 62nd annual awards, a File On 4 programme was recommended by the judges as "an in-depth examination that revealed how nations illicitly procured 'dual use' materials for the development of nuclear weapons."

The investigation, in Autumn 2003, revealed how "rogue" nations, including Iran, had acquired sensitive equipment from British companies for their nuclear arms programmes.